The introduction of hybridoma technology has revolutionized the biomedical field by allowing for the production of unlimited quantities of antibodies of a desired specificity (hereinafter monoclonal antibodies). In 1975, Kohler and Milstein (Nature 256:495 (1975)) disclosed that monoclonal antibodies could be produced by hybrid cell lines (hereinafter hybridomas) prepared by the fusion of spleen cells from an immunized animal with myeloma cells.
Monoclonal antibodies provide highly specific, well-characterized reagents. They have found wide applications in vitro for the identification, purification, and characterization of antigens. When the antigenic determinants recognized by the monoclonal antibodies are cell surface tumor-associated antigens, these reagents may also specifically accumulate at the tumor site. Increasingly they are being tested in vivo for tumor-imaging and therapy (Levy and Miller, Ann. Rev. Med. 34:107 (1983)).
In some cases, treatment With monoclonal antibodies alone has resulted in partial or complete regression of tumors. See papers in the proceeding of the Wistar Symposium on Immunodiagnosis and Immunotherapy with CO17-1A MAb in Gastrointestinal Cancer (Hybridoma 5:Suppl. 1 (1986)). Much effort has also been focused on modifications of monoclonal antibodies for immunodiagnostic and immunotherapeutic applications. For example, monoclonal antibodies can be used for targeted delivery of effective agents in the form of antibody-drug conjugates (Baldwin, in Monoclonal antibody therapy of human cancer. p. 23 (1985) or as bifunctional antibodies (Staerz and Bevan, PNAS 83:1453 (1986)).